MHB Finding k for x is undefined at $x=2$

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For the function defined as f(x) with a piecewise structure, continuity at x=2 requires that k equals the limit of f(x) as x approaches 2. The limit simplifies to 5, indicating that for the function to be continuous at this point, k must be set to 5. The discussion highlights that the discontinuity at x=2 is removable, as it can be resolved by defining k appropriately. Additionally, it distinguishes between types of discontinuities, noting that not all discontinuities imply a hole, as some can involve vertical asymptotes or jumps. Therefore, setting k to 5 ensures continuity at x=2.
karush
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If $f(x)=\begin{cases}
\dfrac{(2x+1)(x-2)}{x-2}, &\text{for } x\ne 2 \\[3pt] k, &\text{for } x=2 \\
\end{cases}$
for what number k will the function be continuous
a. 0 b. 1 c. 2 d. 3 e. 5
---------------------------------
I chose
[e] x is undefined at $x=2$ so
rewrite as $2x+1$
plug in $f(2)=2(2)+1=5=k$

hopefully
probably suggestions etc
 
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for f(x) to be continuous at x = 2 ...

$\displaystyle \lim_{x \to 2} f(x) = f(2)$
 
So discontinuous. Means a hole always?
 
karush said:
So discontinuous. Means a hole always?

not just a hole (a removable discontinuity)

also, a vertical asymptote or a jump (non-removable discontinuities)
 
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